1. Field of the Invention
The present invention relates to a three-dimensional coordinates input apparatus for obtaining three-dimensional coordinates data in order to manipulate an object of a three-dimensional CG (computer graphics) freely by using a stereographic image produced by three-dimensional CG.
2. Description of Background Information
In recent years, interest to the in VR (virtual reality) is growing, for producing an interface that is easy to operate for a person by the use of a stereographic image produced by a three-dimensional CG.
VR pertains to techniques for producing an artificial space into a space around the operator and for moving an object in such an artificial space as if it were a real object. Application of such a VR is expected to a variety of fields such as design, research and development, simulation, and the like. Developments of game machines for game centers, pseudo-experience systems used in showrooms, auxiliary apparatuses for the instruction of assembly works, and the like have been started using VR.
FIG. 1 shows a data glove, as an example of a conventional three-dimensional coordinates input apparatus. As shown, optical fibers 2 for detecting the posture of a hand are adhered onto the surface of the data glove generally denoted by 1. A magnetic sensor 3 for detecting the position of the hand is attached to the portion of the data glove 1 which contacts with back of the hand.
In the three-dimensional coordinates input apparatus with such a construction, data indicative of the position and posture of the hand is generated by the data glove 1 put on by the operator and, further, eye-phones or the like attached to the head of the operator, where the operator arbitrarily moves the hand or fingers in the real space. The position and posture of the image of the hand of three-dimensional CG which is displayed on a display of the eye-phones or the like can be changed on the basis of the acquired data, so that the image displayed in a screen can be grasped or moved realistically.
FIG. 2 shows a touch glove as another example of the conventional three-dimensional coordinates input apparatus. This example shows a touch glove 4 having not only a function of detecting the motion of the hand or the motions of the fingers by the optical fibers (not shown) and the magnetic sensor 3, but also a function to feed back a tactile sensation to a certain degree by a pneumatic pressure.
Since the tactile sensation is produced to a certain degree as mentioned above, a pseudo-experience in a three-dimensional space becomes more realistic.
FIG. 3 shows a manipulator as a further example of a three-dimensional coordinates input apparatus which can produce a certain degree of tactile sensation. Six degrees of freedom are given at a position under a supporting base plate 5 for allowing the manipulator to trace the motion of the hand. In order to allow the manipulator to trace the motions of the fingers, three actuators, namely, first finger portion (not shown), second finger portion 6, and third finger portion 7 are provided.
The first finger portion (not shown) detects the motion of the thumb. The second finger portion 6 detects the motion of the forefinger. The third finger portion 7 detects the motions of the middle finger, third finger, and little finger.
Rotary axes of the three actuators are made coaxial with a joint shaft 8 attached to the supporting base plate 5.
For instance, in such a case that a ball in the screen is likewise grasped by the image of the hand in the screen, an elasticity of the ball is fed back to the fingers of the hand.
The above-described manipulator is designed to manage the motion of the wrist primarily. A master manipulator using a serial link tracing the whole motion of the arm also has been developed.
Furthermore, a method of directly detecting the motion of the hand or fingers by image processing has also been proposed.
All of the foregoing three-dimensional coordinates input apparatuses, however, has an inconvenience that the position detection indicative of the motion of the hand is performed by measuring the position and azimuth of the whole hand relative to a reference position by using the magnetic sensor 3 attached to the data glove 1, so that a response speed is not high enough, so that the motion of the hand in the screen remained slow. Furthermore, with each of the three-dimensional coordinates input apparatuses, it is necessary to put on the data glove 1 or touch glove 4 to the hand or to insert the corresponding finger one by one into the first finger portion, second finger portion 6, and third finger portion 7 of the manipulator, so that there are also inconveniences such that the operations to put on those gloves and to insert the fingers into the finger portions are annoying and, further, the user may have a feeling of discordancy.
The method of directly detecting the motion of the hand or fingers by image processes, on the other hand, has inconveniences such that the recognition precision of those motions are not so good, so it complicates the production of graphic data, so that there arises not only a problem of low response speed but also an increase of the system scale.
The present invention has been made in consideration of the above circumstances and it is an object of the invention to provide a three-dimensional coordinates input apparatus which accurately and easily detects the motion of the hand or fingers in a real space by using a simple construction and doesn't produce a feeling of discordancy for the motion of the hand or fingers in the real space.